Methods for Delivering a Heart Valve Prosthesis

ABSTRACT

The invention provides methods and systems for introducing a delivery device in the heart at or near the apex of the heart, wherein the delivery device includes a prosthesis, advancing the prosthesis to the target site, and disengaging the prosthesis from the delivery device at the target site for implantation. Specifically, the present invention provides valve replacement systems for delivering a replacement heart valve to a target site in or near a heart. The valve replacement system comprises a trocar or other suitable device to penetrate the heart at or near the apex of the heart, a delivery member that is movably disposed within the trocar, and a replacement cardiac valve disposed on the delivery member. The delivery member may further comprise mechanical or inflatable expanding members to facilitate implantation of the prosthetic valve at the target site.

FIELD OF THE INVENTION

The present invention relates generally to methods and systems forcardiovascular surgery. More particularly, the invention relates tomethods and systems for the repair, removal, and/or replacement of heartvalves, and also for providing temporary valves and/or distal embolicprotection during cardiovascular surgery.

BACKGROUND OF THE INVENTION

Various surgical techniques may be used to repair a diseased or damagedheart valve, such as annuloplasty (contracting the valve annulus),quadrangular resection (narrowing the valve leaflets), commissurotomy(cutting the valve commissures to separate the valve leaflets), ordecalcification of valve and annulus tissue. Alternatively, the diseasedheart valve may be replaced by a prosthetic valve. Where replacement ofa heart valve is indicated, the dysfunctional valve is typically removedand replaced with either a mechanical or tissue valve. Tissue valves areoften preferred over mechanical valves because they typically do notrequire long-term treatment with anticoagulants.

A number of different strategies have been used to repair or replace adefective heart valve. Open-heart valve repair or replacement surgery isa long and tedious procedure and involves a gross thoracotomy, usuallyin the form of a median sternotomy. In this procedure, a saw or othercutting instrument is used to cut the sternum longitudinally and the twoopposing halves of the anterior or ventral portion of the rib cage arespread apart. A large opening into the thoracic cavity is thus created,through which the surgeon may directly visualize and operate upon theheart and other thoracic contents. The patient must be placed oncardiopulmonary bypass for the duration of the surgery.

Open-chest valve replacement surgery has the benefit of permitting thedirect implantation of the replacement valve at its intended site. Thismethod, however, is highly invasive and often results in significanttrauma, risk of complications, as well as extended hospitalization andpainful recovery period for the patient.

Minimally invasive percutaneous valve replacement procedures haveemerged as an alternative to open-chest surgery. Unlike open-heartprocedures, this procedure indirect and involves intravascularcatheterization from a femoral artery to the heart. Because theminimally invasive approach requires only a small incision, it allowsfor a faster recovery for the patient with less pain and bodily trauma.This, in turn, reduces the medical costs and the overall disruption tothe life of the patient.

The use of a minimally invasive approach, however, introduces newcomplexities to surgery. An inherent difficulty in the minimallyinvasive percutaneous approach is the limited space that is availablewithin the vasculature. Unlike open heart surgery, minimally invasiveheart surgery offers a surgical field that is only as large as thediameter of a blood vessel. Consequently, the introduction of tools andprosthetic devices becomes a great deal more complicated. The devicemust be dimensioned and configured to permit it to be introduced intothe vasculature, maneuvered therethrough, and positioned at a desiredlocation. This may involve passage through significant convolutions atsome distance from the initial point of introduction.

Accordingly, while heart valve surgery produces beneficial results formany patients, numerous others who might benefit from such surgery areunable or unwilling to undergo the trauma and risks of currenttechniques. Therefore, what is needed are methods and devices forperforming heart valve repair and replacement as well as otherprocedures within the heart and great vessels of the heart that providegreater ease of access to the heart valves than the current minimallyinvasive techniques, while at the same time reducing the trauma, risks,recovery time and pain that accompany more invasive techniques.

SUMMARY OF INVENTION

The present invention provides methods and systems for performingcardiovascular surgery, wherein access to the heart or great vessels isprovided through the apical area of the heart. The apical area of theheart is generally the blunt rounded inferior extremity of the heartformed by the left and right ventricles. In normal healthy humans, itgenerally lies behind the fifth left intercostal space from themid-sternal line.

The unique anatomical structure of the apical area permits theintroduction of various surgical devices and tools into the heartwithout significant disruption of the natural mechanical and electricalheart function. Because the methods and systems of this invention permitdirect access to the heart and great vessels through the apex, it is notlimited by the size constraints which are presented by percutaneoussurgical methods. While access to the heart through the femoral vesselsin percutaneous methods are limited to the diameter of the vessel(approximately 8 mm), access to the heart through the apical area issignificantly larger (approximately 25 mm). Thus, apical access to theheart permits greater flexibility with respect to the types of devicesand surgical methods that may be performed in the heart and greatvessels.

Accordingly, it is one object of this invention to provide methods anddevices for the repair, removal, and/or replacement of heart valves byaccess through the apical area of the heart.

In one preferred embodiment of the present invention, a method fordelivering a prosthesis to a target site in or near a heart is provided.The method comprises introducing a delivery device in the heart at ornear the apex of the heart, wherein the delivery device includes aprosthesis, advancing the prosthesis to the target site, and disengagingthe prosthesis from the delivery device at the target site forimplantation.

The present invention also provides valve replacement systems fordelivering a replacement heart valve to a target site in or near aheart. In one embodiment, the valve replacement system comprises atrocar or other suitable device to penetrate the heart at or near theapex of the heart, a delivery member that is movably disposed within thetrocar, and a replacement cardiac valve disposed on the delivery member.

The valve replacement system may be used to deliver a variety ofprosthetic heart valves, including stented and stentless tissue valves.In another embodiment of the present invention, the delivery member mayfurther comprise mechanical or inflatable expanding members tofacilitate implantation of the prosthetic valve at the target site.

In another embodiment of the present invention, an imaging system may beprovided to view the operating field. The imaging system may be used atany time or throughout the duration of the surgery. Imaging systems arewell-known to one of skill in the art and include transesophageal echo,transthoracic echo, intravascular ultrasound imaging (IVUS), or aninjectable dye that is radiopaque. Cinefluoroscopy may also be utilized.

In one embodiment, the imaging system is deliverable through a catheteror cannula to the operating field. In another embodiment of the presentinvention, an ultrasound transducer may be located on the deliverymember at one or both sides of the expandable balloon. In yet anotherembodiment of the present invention, the ultrasound transducer may belocated on the balloon of the delivery member.

In yet another embodiment of the present invention, the method andsystem may further comprise means to remove at least a portion of thepatient's heart valve by a cutting tool that is disposed on the deliverymember. The cutting tool may be made of an electrically conductive metalthat provides radiofrequency energy to the cutting tool for enhancedvalve removal. The high frequency energy ablation is well known in theart.

In a further embodiment of the present invention, the methods anddevices of the present invention may be adapted to provide a valvedecalcification system, wherein the delivery member is capable ofproviding the dissolution solution to the treatment site by accessthrough the apical area of the heart. The delivery member may be acatheter that is configured with means to both introduce and remove thedissolution solution to the treatment site. The delivery member may alsoprovide means for isolating the treatment site to prevent thedissolution solution from entering into the patient's circulatorysystem. Such means for isolating the treatment site may include abarrier, such as a dual balloon system on the catheter that inflate onboth sides of the treatment site.

The present invention also provides for devices and methods forproviding distal embolic protection. More particularly, the inventionprovides a filter for trapping embolic material while concurrentlyproviding a temporary valve in the same device. The presence of a valvein a filter assembly prevents flush back of embolic material and debris,while still allowing fluid flow into the filter during surgery. Thevalve-filter combination may be compressed and expanded to allow entryinto small blood vessels or other body cavities. In one embodiment ofthe present invention, a valve-filter assembly is implanted in the heartor great vessel of the heart, downstream from the surgical site.

The above aspects and other objects, features and advantages of thepresent invention will become apparent to those skilled in the art fromthe following description of the preferred embodiments taken togetherwith the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial front view of a patient's chest showing areplacement valve delivery device introduced into the apex of the heartthrough the fifth intercostal space.

FIG. 2 depicts a trocar of the replacement valve delivery devicepenetrating the apex of the heart and into the left ventricle.

FIG. 3 shows a balloon expandable delivery member being introduced intothe left ventricle through trocar positioned at the apex of the heart.

FIG. 4 depicts a balloon expandable member being advanced toward theaortic valve.

FIG. 5 shows the placement of the balloon expandable member within astenotic aortic valve.

FIG. 6 shows the expanded balloon expandable member within a stenoticaortic valve.

FIG. 7 shows the insertion of a replacement valve delivery member havinga prosthetic replacement valve disposed around a balloon expandablemember through the apex of the heart.

FIG. 8 is a cross-sectional view of the replacement valve deliverymember positioned within the aorta.

FIG. 9 depicts the expansion of the prosthetic replacement valve by theballoon of the replacement valve delivery member.

FIG. 10 shows a fully-expanded and deployed prosthetic replacement valveand a disengaged replacement valve delivery member.

FIG. 11 is a partial cross-sectional view of the heart showing theprosthetic replacement valve positioned at the aorta.

FIG. 12 shows one embodiment of the delivery member for use in a valvereplacement system.

FIG. 13 shows one embodiment of a valve-filter assembly, positioned inthe aorta, downstream of the aortic valve.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 through 13 show an embodiment of the method and systems for therepair, removal, and/or replacement of heart valves, and also forproviding distal embolic protection and a temporary valve duringcardiovascular surgery.

Valve Replacement Method and System

FIG. 1 is a partial from view of the chest (11) of a patient (10) andshows the position of the valve replacement system (29) in relation toother anatomical landmarks, such as the sternum (13), xiphoid (14), ribs(15), and heart (12). The valve replacement system (29) is depicted asentering the body cavity through the fifth intercostal space (16) andthrough the apex of the heart (12). The valve replacement system (29)may enter the body cavity through various other locations (17A, 17B and17C) in the chest (11).

In one preferred embodiment of the present invention, the valvereplacement system comprises a trocar or other suitable device forpenetrating the apical area of the heart and a delivery member and areplacement prosthetic valve disposed on the delivery member.

The methods and systems of the present invention may be used to implanta variety of prosthetic heart valve assemblies known in the art,including stented and stentless tissue valves. Stented valves may beexpandable by mechanical or balloon expansion devices, or they may beself-expanding. Self-expanding stents may be constructed from metalalloys, such as Nitinol, described in U.S. Pat. No. 6,451,025,incorporated herein by reference.

Alternatively, the methods and devices of the present invention may alsobe used to implant a stentless prosthetic heart valve. In one embodimentof the present invention, the delivery member is adapted to position thetissue valve at the target site and the deliver member further comprisesa means to suture or staple the tissue valve to the valve annulus.

Examples of suitable prosthetic valves are disclosed in the followingcommonly owned patents: U.S. Pat. Nos. 6,682,559; 5,480,424; 5,713,950;5,824,063; 6,092,529; 6,270,526; 6,673,109; 6,719,787; 6,719,788; and6,719,789, incorporated herein by reference. Examples of other valveassemblies suitable for use in connection with the present invention aredescribed in U.S. Pat. Nos. 5,411,552; 6,458,153; 6,461,382; and6,582,462, incorporated herein by reference.

Trocars suitable for use in connection with the present inventiontypically comprise a hollow lumen and a first and second ends. The firstend comprises a means for penetrating the heart tissue and the secondend comprises a port through which the delivery member may be introducedinto the hollow lumen of the trocar and into the heart. FIG. 2 depicts atrocar penetrating through the apex (18) of the heart (12). The movingdirection of the trocar (31) is indicated by the arrow (19). The trocar(31) can enter either the right ventricle 20) or the left ventricle(21). To access the aortic or mitral valve, the trocar (31) wouldpreferably pass through the left ventricle (21). This yields directaccess to the sortic or mitral valve. To access the pulmonary ortricuspid valve, the trocar (31) would preferably pass through the rightventricle (20).

In another embodiment of the present invention, the trocar furthercomprises a valve disposed within the lumen. The valve is designed toreduce significant backflow of blood out of the heart after the trocaris inserted into the beating heart, while at the same time permittingthe introduction of the delivery member and other surgical devices inthrough the trocar. Other suitable trocars and devices are well known inthe art and are disclosed in U.S. Pat. Nos. 5,972,030; 6,269,819;6,461,366; 6,478,806; and 6,613,063, incorporated herein by reference.

The delivery member of the valve replacement system is adapted todeliver the prosthetic valve to the site of implantation, through theapical area of the heart. In one embodiment of the present invention,the delivery member is a rod comprising a mechanical expansion andcontracting device. In one embodiment of the present invention, themechanical expansion and contracting device may comprise a plurality ofhollow wires in a circular arrangement, a grip handle, and a cylindercomprising outwardly angled holes along its perimeter. The prostheticvalve is disposed around the mechanical expansion members in acontracted state and delivered to the target site for implantation. Onceproperly positioned, the mechanical expansion members are expanded bypushing the wires through the angled holes and the prosthetic valve isexpanded for implantation.

In another embodiment of the present invention, the mechanical expansionand contracting device for implanting the prosthetic valve assembly mayinclude a hollow tube surrounded by a plurality of wall panels connectedto a plurality of spring loaded pins extending from the exterior of thetube to a central plate at the interior of the tube. The central platehas spiral shaped edges, such that rotation of the central plate pushesthe pins radially outward. Other mechanical expansion and contractingdevices are more fully described in co-pending U.S. patent applicationSer. No. 10/680,719.

In yet another embodiment of the present invention, the delivery membermay be a hollow tube having an expandable member, such as a balloon.FIG. 3 depicts a delivery member (40) having a balloon (41) beinginserted through the apex (18) and into the left ventricle (21) andadvancing towards the native aortic valve (23) of the heart (12). Oncethe balloon (41) is placed within the aortic valve (23), it may beinflated to widen a stiffor narrowed heart valve (stenotic heart valve)and improving blood flow through the heart and to the rest of the body.This allows the heart to pump more effectively and reduces pressures inthe heart and lungs. Previous methods for performing valvuloplastyrequired the insertion of a catheter at the femoral artery, which isthen guided through the heart and positioned through the diseased heartvalve. The methods and devices of this present invention, however,provide a more direct route to the valve to be treated.

FIG. 4 shows a close-up view of the delivery member (40) and balloon(41) advancing toward the aortic valve (23) where aortic stenosis isevident. As depicted here, the aortic valve has a plurality of valveleaflets (24). In one embodiment, the delivery member (40) comprises atip or distal attachment (42) adapted to receive a variety of auxiliarydevices to assist in the valve replacement procedure. Such auxiliarydevices may include a distal embolic protection assembly, a temporaryvalve, an imaging system, a valve removal system, a valvedecalcification system.

FIG. 5 shows a balloon (41) positioned in the aorta (22) and within theaortic valve (23) and aortic valve annulus (25). The balloon (41) isdepicted as inflating in a radial direction as indicated by the arrows(58) to compress the valvular leaflets (24) against walls of the aorta(22). In FIG. 6, the balloon (41) is fully inflated to widen a stenoticaortic valve (23) by pressing the leaflets (24) against the aorticvails. An inner element (59) may also be used for inserting a guidewirefor controlling tip deflection or a fluid infusion conduit for ballooninflation.

FIG. 7 shows the insertion of the delivery member (40) having a balloonexpansion member (41). A collapsed replacement prosthetic valve (51) isdisposed on the balloon expansion member (41) and is introduced into theport (32) of the trocar (31). The delivery member (40) is depicted aspassing through the apex (18) of the heart (12).

FIGS. 8-9 show expansion of the balloon (41) positioned within thenative aortic valve (23). FIG. 8 is a cross-sectional view of thereplacement valve delivery member (40) comprising a balloon (41) and areplacement valve (51) disposed on an unexpanded balloon (41). Thereplacement valve (51) is depicted here as being positioned within theaortic valve (23). FIG. 9 depicts the radial expansion (52) of theballoon (41) causing the replacement valve (51) to press against theaortic valve leaflets (24) of the aortic valve (23) against the annulus(25).

FIG. 10 shows the deployed valve in its fully expanded state. Thereplacement prosthetic valve (51), as depicted here, comprises a basering (57) and a support structure or stent (54) with tabs (56) tosupport the tissue valve (55). Once the prosthetic valve (51) isimplanted, the balloon (41) is then deflated and the delivery member(40) is withdrawn from the body in the direction indicated by the arrow(53). FIG. 11 shows the implanted replacement valve (51) positioned inthe aortic valve position.

Imaging Systems

An imaging system to view the operating field may be used at any time orthroughout the duration of the surgery. Imaging systems are well-knownto one of skill in the art and include transesophageal echo,transthoracic echo, intravascular ultrasound imaging (IVUS), or aninjectable dye that is radiopaque. Cinefluoroscopy may also be utilized.In one embodiment, the imaging system is deliverable through a catheteror cannula to the operating field.

Intravascular ultrasound (IVUS) uses high-frequency sound waves that aresent with a device called a transducer. The transducer may be coupled tothe delivery member of the present invention. In this arrangement, thesound waves bounce off of the walls of the vessel or heart and return tothe transducer as echoes.

In one embodiment of the present invention, a delivery member mayinclude at least one ultrasound transducer to provide an image of thetarget site before, during, and after valve implantation. FIG. 12 showsanother embodiment of the delivery member of present invention. In thisembodiment, the delivery member comprises an inner member (49A) that isretractable within the lumen of an outer member (49B). Upon deploymentof the delivery member (40), the distal end (44) of the inner member(49A) is exposed past the end (45) of the outer member (49B).

The distal end (44) of the inner member comprises an expandable balloon(41) in fluid communication with the fluid infusion mechanism (48) andthe handle (43) of the delivery member, by which the balloon (41) may beeither inflated or deflated. The inner member (49A) of the deliverymember (40) further comprises ultrasound transducers (47) adjacent tothe expandable balloon (41) and a tip or distal attachment (42) which isadapted to receive a variety of auxiliary devices to assist in the valvereplacement procedure. Such auxiliary devices may include a distalembolic protection assembly, a temporary valve, an imaging system, avalve removal system, a valve decalcification system.

While ultrasound transducers disclosed here are located adjacent to theballoon, it is appreciated that the ultrasound transducer may be placedat any location on the delivery member, on the balloon, and/or on thetip or distal attachment.

Valve Removal Systems

The present invention also provides a method or system for removing thevalve with a valve removal device by access through the apical area ofthe heart. By way of example, the valve removal may be accomplished astaught in co-pending U.S. patent application Ser. Nos. 10/375,718 and10/680,562, which are incorporated herein by reference as if set forthin its entirety.

In one embodiment of the present invention, the method may furthercomprise the step of removing at least a portion of the patient's heartvalve by means of a cutting tool that is disposed on the deliverymember. In another aspect of the present invention, the cutting tool maybe made of an electrically conductive metal that provides radiofrequencyenergy to the cutting tool for enhanced valve removal. The highfrequency energy ablation is well known in the art.

In another embodiment of the present invention, the delivery memberincludes cutting means comprising a plurality of jaw elements, each jawelement having a sharp end enabling the jaw element to cut through atleast a portion of the native valve. In another aspect, the cuttingmeans comprises a plurality of electrode elements, whereinradiofrequency energy is delivered to each electrode element, enablingthe electrode element to cut through at least a portion of the nativevalve. In a further aspect of the present invention, the cutting meanscomprises a plurality of ultrasound transducer elements, whereinultrasound energy is delivered to each transducer element enabling thetransducer element to cut through at least a portion of the nativevalve.

Valve Decalcification Systems

The formation of atherosclerotic plaques and lesions on cardiovasculartissue, such as blood vessels and heart valves, is a major component ofcardiovascular disease. A variety of different methods have beendeveloped to treat cardiovascular diseases which are associated withcalcified atherosclerotic plaques and lesions. Such methods includemechanical removal or reduction of the lesion, such as bypass surgery,balloon angioplasty, mechanical debridement, atherectomy, and valvereplacement.

Calcified atherosclerotic plaques and lesions may also be treated bychemical means which may be delivered to the affected area by variouscatheter devices. For example, U.S. Pat. No. 6,562,020 to Constantz etal. discloses the treatment of vascular calcified lesions by using anacidic dissolution solution and a catheter fluid delivery system capableof localized flushing a vascular site. Suitable catheter devices includethose described in U.S. Pat. No. 6,562,020, which is incorporated hereinby reference as if set forth in its entirety.

Accordingly, in another embodiment of the present invention, the methodsand devices of the present invention may be adapted to provide a valvedecalcification system, wherein the delivery member is capable ofproviding the dissolution solution to the treatment site by accessthrough the apical area of the heart. Suitable dissolution solutions areknown in the art and are generally characterized as those which arecapable of increasing the proton concentration at the treatment site toa desired level sufficient to at least partially dissolve the mineralcomponent of a calcified atherosclerotic lesion.

The delivery member may be a catheter that is configured with means toboth introduce and remove the dissolution solution to the treatmentsite. The delivery member may also provide means for isolating thetreatment site to prevent the dissolution solution from entering intothe patient's circulatory system. Such means for isolating the treatmentsite may include a barrier, such as a dual balloon system on thecatheter that inflate on both sides of the treatment site.

Temporary Valve

During valve replacement surgery, the function of the native valve beingreplaced is halted and the natural fluid flow blood in the heart istherefore disrupted. This, in turn, may result in significant backflowblood pressure in the heart and vessels. There is therefore a need toprevent or reduce the backflow blood pressure that results when thenatural valve function is halted during replacement valve surgery.

The present invention provides a means of providing a temporary valveeither before or concomitantly with the delivery of a replacement heartvalve.

In one embodiment of the present invention, the delivery membercomprises a temporary valve, which may be deployed at a desired locationin a collapsed state, expanded and secured to the walls of a heart orblood vessel, and then re-collapsed and removed from the body aftercompletion of the valve replacement surgery. The temporary valve may beprovided as a tip attachment to a deliver member comprising thereplacement valve. Alternatively, the temporary valve may be disposed ona separate delivery member in a manner similar to the replacement heartvalve.

In a preferred embodiment of the present invention, the temporary valveis deployed at a location that is sufficiently close to thenon-functioning valve. The location of the temporary valve may be placedeither upstream or downstream of the non-functioning valve.

Distal Embolic Protection Assemblies

In valve repair or replacement surgery, manipulation of the heavilycalcified valves may result in dislodgment of calcium and valve or othersurrounding tissue, with subsequent embolization and blockage. Althoughatheromatous debris most frequently embolizes in the brain, otheraffected body sites include the spleen, kidney, pancreas, andgastrointestinal tract. Embolization and blockage to these peripheralorgans can lead to tissue ischemia or death. A need therefore exists forsafely containing embolic material during cardiovascular surgery.

In one embodiment of the present invention, a valve-filter assembly isprovided. This valve-filter assembly may be implanted downstream fromthe site before surgery is to be performed. A preferred embodiment ofthe valve-filter assembly is depicted in FIG. 13, which shows avalve-filter assembly (61) positioned in the aorta (22) and downstreamof the aortic valve (23). The temporary valve-filter assembly (61) iscomprised of a temporary valve (62) and a filter (63) extendingtherefrom. The valve-filter assembly provides distal embolic protectionand may be delivered by a catheter or cannula or any conventional methodto the downstream side of the native aortic valve (23). After thetemporary valve-filter assembly is positioned at a desired location(64), it is deployed to serve the dual functions of a temporary checkvalve and a filter to capture any loose emboli or debris during surgery.

A valve is included in the distal embolic protection assembly to providethe dual function of acting as a temporary valve during valvereplacement surgery and preventing embolic material from escaping outfrom the filter. Adding a one-way valve at the inflow of a filterprevents embolic material from escaping, thus reducing the incidence ofembolization and blockage. A valve would concurrently provide atemporary valve for use during valve surgery. Combining both a filterand a valve in the same arrangement also creates a more compact deviceallowing more space for conducting other procedures. In aortic repairand replacement surgeries, for example, there is limited space inbetween the aortic valve and the innominate branch. Combining a filterand a valve in a compact device allows more space for devices used forthe valve repair or replacement procedure.

A difficulty inherent in the percutaneous implantation of valve-filterdevices, as described above, is the limited amount of space that isavailable within the vasculature. The device must be dimensioned andconfigured to permit it to be introduced into the vasculature,maneuvered therethrough and positioned downstream of the treatment site.This may involve passage through significant convolutions at somedistance from the initial point of introduction. Once in position, thedevice must be deployable to a sufficiently large cross-section toeffectively strain substantially all of the blood passing therethroughwithout unacceptably reducing its flow rate. Additionally, the use orthe presence of such device must not interfere with the treatment of thevasculature site, nor may the treating device interfere with thefunction of the embolic capture device.

Moreover, it is crucial that material captured by the filters describedabove are contained and not allowed to leave the proximity of thefilter. In valve repair surgery, for example, it is important thatmaterial dislodged during surgery and trapped by a filter placed inbetween the aortic valve and innominate branch is not allowed to leavethe filter during back flow and hence enter the coronaries. Preventingdebris from leaving the filter is especially important when largerparticles are present that does not easily attach to the filtermaterial.

The filter of the valve-filter assembly may be a mesh of any size andshape required to trap all of the embolic material while still providingsufficient surface area for providing satisfactory blood flow duringuse. The filter may be a sheet or bag of different mesh sizes. In apreferred embodiment, the mesh size is optimized taking intoconsideration such factors as flow conditions, application site, size offilter bag, and rate of clotting.

Although the invention has been described with reference to preferredembodiments and specific examples, those of ordinary skill in the artwill readily appreciate that many modifications and adaptations of theinvention are possible without departure from the spirit and scope ofthe invention as claimed hereinafter.

1-26. (canceled)
 27. A method for delivering a heart valve prosthesis toa target site in a body, the method comprising: introducing a deliverydevice having a heart valve prosthesis releasably coupled to thedelivery device into a chamber of a heart through an apical area of theheart; advancing the heart valve prosthesis to a target site in a body;and implanting the heart valve prosthesis at the target site.
 28. Themethod of claim 27, further comprising removing the delivery device fromthe body.
 29. The method of claim 27, wherein the introducing thedelivery device into the heart through the apical area of the heartcomprises advancing the delivery device through a fifth left intercostalspace from a mid-stemal line of the body.
 30. The method of claim 27,wherein the chamber of the heart comprises a left ventricle of theheart.
 31. The method of claim 30, wherein the target site comprises anative aortic valve or a native mitral valve.
 32. The method of claim27, wherein the chamber of the heart comprises a right ventricle of theheart.
 33. The method of claim 32, wherein the target site comprises anative pulmonary valve or a native tricuspid valve.
 34. The method ofclaim 27, wherein the heart valve prosthesis comprises a tissue valvecoupled to a collapsible and expandable support structure.
 35. Themethod of claim 27, wherein the introducing the delivery device into theheart through the apical area of the heart comprises: penetrating atrocar comprising a hollow lumen through the apical area of the heartand into the chamber of the heart; and passing the delivery devicethrough the hollow lumen of the trocar and into the chamber of theheart.
 36. The method of claim 27, wherein the apical area of the heartcomprises a blunt rounded inferior extremity of the heart from by a leftventricle and a right ventricle of the heart.
 37. A method fordelivering a heart valve prosthesis to a target site in a body, themethod comprising: inserting a trocar comprising a hollow lumen throughan apex of a heart and into a chamber of the heart; passing a deliverydevice having a heart valve prosthesis releasably coupled to thedelivery device through the hollow lumen of the trocar and into thechamber of the heart; advancing the heart valve prosthesis to a targetsite in a body; and implanting the heart valve prosthesis at the targetsite.
 38. The method of claim 37, further comprising removing thedelivery device from the body.
 39. The method of claim 37, wherein theinserting the trocar through the apex of the heart comprises advancingthe trocar through a fifth left intercostal space from a mid-sternalline of the body.
 40. The method of claim 37, wherein the chamber of theheart comprises a left ventricle of the heart.
 41. The method of claim40, wherein the target site comprises a native aortic valve or a nativemitral valve.
 42. The method of claim 37, wherein the chamber of theheart comprises a right ventricle of the heart.
 43. The method of claim42, wherein the target site comprises a native pulmonary valve or anative tricuspid valve.
 44. The method of claim 37, wherein the heartvalve prosthesis comprises a tissue valve coupled to a radiallycollapsible and expandable support structure.
 45. A method fordelivering a heart valve prosthesis, the method comprising: introducinga delivery device having a heart valve prosthesis releasably coupled tothe delivery device into a left ventricle of a heart through an apex ofthe heart; advancing the heart valve prosthesis to a native aortic valvein a body; and implanting the heart valve prosthesis at the nativeaortic valve.